1. Field of the Invention
The present invention is directed to a hub for a motor vehicle clutch with a driver connectable to a shaft and a ring element arranged on a circumference of the driver, wherein the ring element has a profile for receiving torque conducted into the shaft from friction facings arranged on the ring element.
2. Description of the Related Art
Hubs for motor vehicle clutches that have drivers arranged on shafts and ring elements arranged on the drivers are known and are used in multidisk clutches to hold friction facings on an input shaft of a transmission so that the friction facings are fixed with respect to rotation and axially displaceable relative to the input shaft. The prior art hub is usually forged and subsequently machined by cutting in its radial inner and outer areas. The profile of the prior art hub typically has a splined shaft profile and serves to hold the friction facings directly or to hold facing springs connected with the friction facings.
A disadvantage of the prior art hub is that the manufacture by cutting is cost-intensive. Further, because of its construction, the prior art hub has a high material requirement and is very heavy. The heavy weight leads to unwanted inertia in the assembled state during acceleration of the hub.
The object of the invention is to provide a hub for a transmission input shaft in a motor vehicle clutch that is inexpensive to produce and has the lowest possible weight.
The object is met according to an embodiment of the present invention in that the hub element has a ring element comprising a circumferential sheet metal part which is shaped to a required profile.
The hub according to the present invention may be constructed with very thin walls because the ring element is manufactured as a sheet metal part. The hub accordingly has a particularly low weight in its radial outer area and therefore has an especially low inertia in its mounted state. Since the profile of the ring element for receiving the friction facings is formed by shaped portions of the sheet metal part, the present invention eliminates the costly requirement for subsequent machining of the profile by cutting. Therefore, the hub according to the present invention is manufactured particularly economically. A further advantage of the inventive design is that the surface of the profile has a particularly high-resistance to wear because of the cold hardening resulting from the shaping of the sheet metal part.
The sheet metal part of the ring element may be mounted, for example, directly on a forged driver part that is fastenable to the shaft. However, this forged part would be very heavy. To further reduce the weight of the hub, the driver according to the present invention has a sheet metal part with a tubular collar provided for enclosing the shaft and a rim arranged perpendicular to the collar. Furthermore, the collar may often be manufactured with very great accuracy by the deep-drawing method. Therefore, subsequent machining of the area of the driver contacting the shaft is not necessary This facilitates a further reduction in the manufacturing costs of the hub according to the present invention.
The hub may be manufactured, for example, in one piece from a sheet metal shaped by a deep-drawing method. However, the hub resulting from this manufacturing method is limited to having simple shapes which results in a very limited stability of the hub and in an asymmetric introduction of force into the hub. Instead of manufacturing the hub from one sheet metal piece, the driver manufactured from one sheet metal part and the ring element manufactured from another sheet metal part may be connected with one another in a positive engagement and/or a material engagement according to another embodiment of the present invention. This embodiment provides the hub with a particularly high stability.
According to a further embodiment, the ring element is provided with a profile of virtually any shape when the sheet metal part of the ring element is constructed as a sheet metal strip with interconnected ends. In this way, the profile may be produced by an undulating or corrugated shaping of the sheet metal strip.
The ring element has a particularly high stability when the sheet metal part of the ring element is constructed as a pipe piece with indentations corresponding to the profile.
According to another embodiment, the driver further includes a sleeve which is connected at the radial inner end of the sheet metal part of the driver. The sleeve is used for fastening the driver to the shaft which contributes to increased stability of the driver. For this purpose, the sleeve may be constructed as a rotating part with high strength and particularly small dimensions.
To further increase stability of the driver, two sheet metal parts may be used that are arranged in a mirror-inverted arrangement. This construction allows the driver to be arranged in any desired manner such, for example, as with beads or in a box-shaped manner.
In yet another embodiment, the outer profile of the sheet metal part of the driver corresponds to the radial inner area of the sheet metal part of the ring element such that very high forces can be transmitted to the sheet metal part of the driver from the sheet metal part of the ring element.
A torque damper may be integrated in the hub according to the invention in a particularly economical manner when it is arranged between the sheet metal parts of the ring element and driver. In this way, the sheet metal parts of the ring element and driver, which must be manufactured separately in any case, need only be shaped in a corresponding manner in their areas facing the torque damper.
The hub with the torque damper according to the present invention has a particularly low weight when the torque damper has a housing manufactured from shaped sheet metal and when the housing has two legs which are arranged parallel to one another and which face radially inward from the ring element.
A result of this construction is that the torque damper contributes to increase-stiffness of the hub according to the invention in the area of the hub adjoining the ring element.
According to a further embodiment, the ring element is reliably held in its intended axial position when the sheet metal part of the ring element has lugs which are bent radially inward and which laterally contact the structural component part of the hub component that adjoins the ring element. The structural component part of the hub that adjoins the ring element may, for example, be the torque damper or the driver.
The hub according to yet another embodiment of the present invention has a particularly small number of structural component parts when two sheet metal parts of the driver are constructed to adjoin one another and have a collar for forming the ring element at the radial outer circumferences.
To further reduce the quantity of structural component parts of the hub according to the invention, the sheet metal parts of the driver may have, at their radial inner boundary, at least one collar provided for fastening to the shaft. The collar may be constructed to correspond to a profile of the shaft so that no intermediate sleeve is required for the connection of the hub to the shaft.
The sheet metal parts of the driver may be connected with one another in a material engagement or in a positive engagement in any desired manner. In particular, the sheet metal parts may be riveted together. According to another embodiment of the invention, additional structural component parts to be mounted for the connection and heating of the sheet metal parts caused by riveting can be avoided when the sheet metal parts of the driver have lugs which engage around one another. Accordingly, the hub according to the invention may be produced and mounted in a particularly economical manner.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.